Radiator sealing valve



Feb. 1l, 1947. u E, ESHBUGHv 2,415,475 i RADIATOR SEALING VALVE Filed Apri; 15, 1944 Gttorneg Patented Feb. A11, 1947 f 41ans d ortica aAnrAron sEAuNG VALVE Jesse E. Eshbaugh, Flint, Mich.,'assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 15, 1944, Serial N0.'53l,157

f2 Claims. (Cl. 23S-*92) Most automobiles are driven by liquid cooled engines and the conventional cooling system includes a jacketed cylinder block connected by a rubber hose with a light weight radiator having thin walled tubes forA quick heat transfer from liquid flowing through the tubes to an air stream owing against the outside of the tubes.

For less loss by evaporation of hot liquid and increased heat dissipation with a relatively small quantity of cooling liquid and a small size radiator unit, the recent practice has been to incorporate in the radiator iiller cap a vent closure so that the system is sealed and the expansion of system contents, as the operating temperature rises, produces an internal system operating pressure. As the pressure goes up and reduces liquid boiling tendency, the liquid absorbs more heat in the en gine jacket for greater dissipation in the radiator. On the other hand greater strain is placed on the radiator and its hose connections and to prevent bursting, the range of system pressure is conftrolled bya pressure relief valve and a vacuum relief valve for opening the vent. As ordinarily constructed both valves are normally seated at all times except i'or the infrequent momentaryl part of the valveoper- As seen in Figure 2 the system is sealed fromv the ven* pipe t by valve mechanism within the ller spout 9 and formed as a unit assembly with the llercap l@ for removal therewith. A dependent stud i2 carried by the cap slidably receives the domed central portion of a valve 'i3 carrying a sealing gasket lll to seat on an inturned flange it at the base of the nller spout t. The valve it normally is held on its seat by a coil y spring i6 interposed between the valve and the intervals of excess pressure relief whereas the primary advantages of a sealed system are obtained only at times of high system operating temperatures. At the lower cooling liquid temperature internal system pressure serves no useful purpose but maintains continued strain on the more delicate or weaker parts of the sys tem and, therefore, promotes leakage and breakdown.

It is an object of the present invention to eliminate unnecessary stress on the cooling system while retaining the advantages of pressure operation to relieve or reduce radiatorfatigue. It is proposed that the system'vent, instead of being normally closed, be open at all times except when the motor is hot and better cooling eiliciency is needed. To this end the vacuum relief valve is controlled by a thermostat which is directly responsive to internal vsystem pressure and closes thelvent only after a predetermined system ternperature is exceeded. Otherwise the valves controll system operating pressure as heretofore and relieve excess high and low internal pressures.

l In the accompanying drawing Figure 1 is side elevation of the frontpart of awater cooled engine-and its associated radiator; Figure 2 is an enlarged sectional view of the radiator filler cap and valve assembly; Figure 3 is a transverse view taken on line 3-3 of Figure 2 and Figure 4 shows cap it.

Press fitted or otherwise secured within the central domed portion of the valve it is the'upper, end of the valve cage or housing it whose lower end extends down into the top tank t so that ii the cooling system is completely full of liquid the lower end ol the valve cage i6, together with the coiled bimetal thermostat il contained within the cage, will be submerged in the cooling liquid. At its upper end the cage it has a central opening it in communication with the interior of the filler spout through one or more openings it in the top of the valve i3 and the opening i3 is surrounded by an annular raised rib 2t providing a seat for an inwardly opening valve comprising a gasket ring'zl, a backing plate 22 and a central stud 23. The lower end of the stud has a socket receiving and being secured on the ballv end of a stem 2li which projects through the bottom wall of a rotatable ybarrel or valve stem guide 25. The

.lower end of the stem is provided with an annular groove to which is ntted' a snap ring retainer 26 arrangedr for abutment with the bottom wall of the barrel 25 to limit relative outward movement of the valve stem under influence of a coil spring 2l contained within the barrel.

Near its upper end the rotatable barrel has a helical groove or screw thread formation 28 to receive therein circumferentially spaced lips 29 arranged in ahelical path and "formed in" a disk stamping 30 seated at its rim against a shouldered portion of the housing I4 and retained in place byfseveral deformable bosses 3|. A barrel 25v is also provided with an axially extending groove 32 im which exi-.ends snmiurned esist the eentral terminal of the thermostat coil llv and the outer terminal oi the'coil is anchored by an out- Y wardlyextending ear ntted toV an upstanding leg Il pressed out of the cover cap 14 at the. bottom of the valve cage I8. i

Since it is on the system side of the valves and immediately adjacent the cooling liquid the coil 'i1 is directly responsive to changes in cooling liquid temperature and its expansion and contraction will impart to the barrel arcta-tion. .By

reason of the screw threaded mounting, the bar rel, upon rotation, also moves axially toward or away from the valve seat 20 and conditions the valve to Abe seated under influence of its spring.

21 or `to, be unseated by thev abutment of the barrel with the stop 28l on the valve stem. In-

the sealed position of the parts shown in Figure 2 the system is operating with liquid at a relatively high temperature and under internal pressure for maximum heat transfer. Should the internal pressure tend to rise beyond the predetermined degree the pressure on the underside of the valve will cause the spring i6 to deflect and lift the valve luntil the excess pressure is relieved. On the other hand, in the event system pressure drops below atmospheric pressure the valve 2| will be sucked down to substantially equalize internal and external pressures. At any time that temperature in the steam space immediately below the valve drops below a predetermined value, whether the system 4is idle or operative, the response ofthe thermostat rotates the barrel 2s fui-ably to unseat the vaivezi and,

-therefore, eliminate pressure-dlierenoes within and outside the system.

Thus the system is relieved of internal preswenn .moei conditions wher; the tne'rmitr 'might not cool .oir as fast as other parts oi the .cooling system.

I claim:

1. In an engine cooling system'havins an overilow vent. an outwardly Vopening pressure relief y valve for the system overilow vent, provided with a port therein, an. inwardly opening valve for the port, having a dependent stem, a rotary barrel surrounding the stem as a guide therefor, a

i seating spring between the barrel and valve, a

sures fat all times except when higher operating emclency. Sinoe low temperature operationdoes not require a closed system the thenostatsel'ves to keep theuyent open for minimum stress on the parts. When water isemployed as' the temperatures demand increased heat dissipation I coolant'the thermostat'is selected'to act at a temperature of aroimd 190 F..in'urglng the valve to closedpositlon to afford a 'completelyl sealedsystem above the selected temperature. The vacuum valve being spring supported canbe opened by reduction of pressure inthe Ysystem without necessarily having acorresponding `re 30 Number duction of temperature at the thermostat.

"is oi advantage in that it makes'rener `or vaeuum stop carried by the stem to engage the barrel and limit relative outward movement of the valve under 'the force of its seating spring, a screw threaded mounting for the barrel compelling axial shift of the barrel incidentzto its rotation and a temperature responsive coil surrounding .the guide barrel on 'the system side of the valve.

2. In an engine cooling system having a ilxed valve seat surrounding a system vent opening, an outwardly opening pressure relief valve engaging said seat and having a vent opening therein, an inwardly opening depression relief valve for closing the vent opening in said pressure relief valve, a thermostat on the system side oi said valves directly exposed to system temprature, a pair of axially shlftable members joined respectively to the thermostat and said depression relief valve and'having between them spring means yieldingly urging them apart and stop abutments on said members to limit their relative travel .under spring force.

.meen E. ESHBAUGH. REFERENCES orrnn The following references are of record in the ille of this patent:-

UNITED STATES PATENTS British Apr. 1, 192e 

